This invention relates to security devices and, more particularly, it relates to a portable and removable door locking device.
The prior art shows several door security devices which are supplemental to the locks found on doors. These various supplemental security devices all suffer from various disadvantages that are overcome by the instant invention.
For example, U.S. Pat. No. 5,098,138 to Vandewege discloses a device with an elongate rod extending up to the proximity of the doorknob. In one embodiment, the device is attached by way of screws to the door. An alternative embodiment of the Vandewege patent shows the device clamped between the bottom of the door and the door knob. This device is relatively large in size and has a rather complicated wedge member utilized at the bottom of the door to stop the door from opening.
U.S. Pat. No. 4,421,348 to Kahn discloses a door guard with a folding locking member that opens to create a diagonal leg to prevent opening of the door. This patent discloses a separate detached foot piece that the diagonal leg may rest in. This device also has an upstanding leg which braces against the inside surface of the door with a lip which extends partially under the door. No particular means is provided to secure the upstanding leg to the door and therefore the security provided by this particular device is less than optimal. Moreover, the folding diagonal leg may be extended and placed on the floor or the friction pad without being placed under any particular amount of compression to secure the device in place. Moreover, the security of this device is extremely dependant upon the adhesion of the friction pad to a floor surface which will depend upon the amount of compression that the diagonal leg is under. Also, the Kahn invention does not disclose any adjustment means for taking into account different gaps between the doors and floor surfaces.